Explore topic-wise InterviewSolutions in Current Affairs.

This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.

1.

Identify the wrong statement.

Answer»

AMONGST the isoelectronic species, smaller the positive charge on cation, smaller is the ionic radius
Amongst isolectric species greater the negative charge on the anion larger is the lonic radius
Atomic radius of the elements increases as ONE moves down the FIRST group of the periodic table
Atomic radius of the elements DECREASES as one moves across from left to right in the 2nd period of the periodic table .

Answer :A::B::C::D
Discussion
2.

Identify the worn statement in the following

Answer»

OZONE layer does not perit infrared radiation from the sun to reach the earth
Acid RAIN is mostly because of oxides of NITROGEN and SUPHUR
Chlorofluoro hyudrocarbons are responsible for ozone layer DEPLETION
Green house effect is responsible for globol warming

Answer :A
Discussion
3.

Identify the valence electron for CO_(3)^(2-)

Answer»

42
24
8
20

Solution :VALENCE electrons of `C= 4` , Valence electrons of `3 - 0 = 3 XX 6 = 18` unit negative charge = 2
` :. ` Total number of valence electrons ` = 4 + 8 + 2 = 24`.
Discussion
4.

Identify the type of redox reaction taking place in the following . 2overset(+1)Koverset(+5)CIoverset(-2)O_(3_((s)))to2overset(+1)Koverset(-1)CI_((s))+3overset(0)O_(2_((g)))

Answer»

SOLUTION :DECOMPOSITION REACTION
Discussion
5.

Identify the type of reaction. (i) HCHO + HCN rarr CH_(2)(OH)CN (ii) CH_(3)Cl+KOH_((aq))rarrCH_(3)OH+KCl (iii) CH_(3)N=NCH_(3)overset(Heat)rarrCH_(3)-CH_(3)+N_(2) (iv) CH_(3)CH(Br)-CH(Br)-CH_(3)ZnrarrCH_(3)CH=CHCH_(3)+ZnBr_(2)

Answer»

(i) SUBSTITUTION, (ii) ADDITION, (iii) Elimination, (iv) Elimination
(i) Addition, (ii) Substitution, (iii) Decomposition, (iv) Elimination
(i) Addition, (ii) Addition, (iii) Substitution, (iv) Substitution
(i) Substitution, (ii) Elimination, (iii) Addition, (iv) Substitution

ANSWER :B
Discussion
6.

Identify the type of isomerism exhibited by the following compounds ? C_5H_12

Answer»

SOLUTION :CHAIN ISOMERISM.
Discussion
7.

Identify the type of isomerism exhibited by the following compounds ?CH_3 - CH = CH - CH_2CH_3

Answer»

SOLUTION : GEOMETRICAL ISOMERISM and POSITION isomerism
Discussion
8.

Identify the type of energy change (ionization energy, energy of atomization, etc) show by each of these steps in the Born Haber cycle for potassium chloride. State with a reason whether the step is exothermic or endothermic. a) 1//2 CI_(2)(g) rarr CI(g) "" b) CI(g) rarr CI^(-)(g) ""c) K(s) rarr K (g) d) K(g) rarr K^(+) (g) + e^(-) "" e) K (s) +1//2 CI_(2) (g) rarr KCI (s) "" f) KCI (s) rarr K^(+) (g) + CI^(-) (g)

Answer»

Solution :(a)half of bond enthalpy(b) First electron affinity
(c) Enthalpy of atomization(d) First IONIZATION ENERGY
( E) Enthalpy of formation(F) Lattice enthalpy - ENDOTHERMIC
Discussion
9.

Identify the type of isomerism exhibited by the following compounds ? CH_3CH_2CH_2CH_3

Answer»

SOLUTION :CHAIN ISOMERISM
Discussion
10.

Identify the type of hybridisation present in c-atoms of diamond.

Answer»

Solution :The electronic configuration of CARBON is `1s^(2)2s^(2)2P^(2)` (ie) the valence electrons spread in s and p orbitals.
In ORDER to create B COVALENT bonds in diamond, one s- orbital mixes with three p - orbitals to form `sp^(3)` hybridisation .
Discussion
11.

Identify the true combination

Answer»

<P>(I) (i) P
(II) (i) Q
(III) (iii) R
(IV) (ii) S

Answer :A
Discussion
12.

Identify the substances undergoing oxidation and reduction in the following reactions. SO_(2)+2H_(2)Sto2H_(2)+3S

Answer»

Solution :`H_(2)S` is UNDERGOING OXIDATION and `SO_(2)` is undergoing reduction.
Discussion
13.

Identify the substances undergoing oxidation and reduction in the following reactions. 2NaOH+Cl toNaCl+NaClO+H_(2)O

Answer»

SOLUTION :`Cl_(2)` is undergoing both oxidation and REDUCTION.
Discussion
14.

Identify the substance oxidised reduced, oxidising agent and reducing agent for each of the following reactions : (a) 2AgBr_((s))+C_(6)H_(6)O_(2(aq))to2Ag_((S))+2HBr_((aq))+C_(6)H_(4)O_(2(aq)) (b) HCHO_((l))+2[Ag(NH_(3))_(2)]_((aq))^(+)+3OH_((aq))^(-)to2Ag_((s))+HCOO_((aq))^(+)+4NH_(3(aq))+2H_(2)O_((l)) ( c) HCHO_((l))+2Cu_((aq))^(2+)+5OH_((aq))^(-)toCu_(2)O_((s))+HCOO_((aq))^(-)+3H_(2)O_((l)) (d) N_(2)H_(4(l))+2H_(2)O_(2(l))toN_(2(g))+4H_(2)O_((l)) (e) Pb_((s))+PbO_(2(s))+2H_(2)SO_(4(aq))to2PbSO_(4(s))+2H_(2)O_((l))

Answer»

SOLUTION :
Discussion
15.

Name the substance oxidised and the substance reduced, and also identify the oxidising agent and reducing agents in the following reactions : (a) 3MnO_(2) +4Al to 3Mn +2Al_(2)O_(3) (b) Fe_(2)O_(3) + 3CO to 2Fe + 3CO_(2) (c) SO_(2) + 2H_(2)S to 3S +2H_(2)O

Answer»

Solution :Writing the oxidation numbers of all atoms involved in the given REACTION, we have

From the above it is clear that the oxidation number of Al increases from 0 to +3. Hence, Al UNDERGOES oxidation and acts as a reducing agent. In `MnO_(2)`, the oxidation number of Mn decreases from +4 to 0. Therefore, `MnO_(2)` undergoes reduction and acts as an OXIDISING agent.
Discussion
16.

Identify the substance undergoing oxidation, the substance undergoing reduction, the oxidising agent and the reducing agent in each of the following reactions. Cr_(2)O_(7)^(2-)+6Fe^(2+)+14H^(+)to2Cr^(3+)+6Fe^(3+)+7H_(2)O

Answer»

SOLUTION :For the given reaction, we have

From the above, it is clear that the OXIDATION number of `Fe^(2+)` ion increases form +2 to +3. THEREFORE, `Fe^(2+)` ion gets oxidised and acts as a reducing agent. In `Cr_(2)O_(7)^(2-)` ion, the oxidation number of Cr decreases from +6 or +3. Hence, `Cr_(2)O_(7)^(2-)` ion gets reduced and acts as an oxidising agent.
Discussion
17.

Identify the substance oxidised and reduced, oxidising agent and reducing agent for each of the following reactions (a) 2AgBr(s)toC_(6)H_(6)O_(2)(aq)to2Ag(s)+2HBr(aq)+C_(6)H_(4)O_(2)(aq) (b) HCHO(l)+2[Ag(NH_(3))_(2)]^(+)(aq)+3OH^(-)(aq)to2Ag(s)+HCOO^(-)(aq)+4NH_(3)(aq)+2H_(2)O(l) (c ) HCHO(l)+2Cu^(2+)(aq)+5OH^(-)(aq)toCu_(2)O(s)+HCOO^(-)(aq)+3H_(2)O(l) (d) N_(2)H_(4)(l)+2H_(2)O_(2)(l)toN_(2)(g)+4H_(2)O(l) Pb(s)+PbO_(2)(s)+2H_(2)SO_(4)(aq)to2PbSO_(4)(s)+2H_(2)O(l)

Answer»

SOLUTION :
Discussion
18.

Identify the substance acting as oxidant or reductatant if any in the following: (i) AlCl_(3) + 3K rarr Al + 3KCl (ii) SO_(2) + 2H_(2)S rarr 3S + H_(2)O (iii) BaCl_(2) + Na_(2)SO_(4) rarr BaSO_(4) + 2NaCl (iv) 3I_(2)+ 6NaOH rarr NalO_(3) + 5Nal + 3H_(2)O

Answer»


ANSWER :(i) Oxidant`-AlCl_(3)`, Reducant `-K`
(II) Oxidant `-SO_(2)`, Reducatn `- H_(2)S`
(iii) NONE
(IV) Oxidant`-I_(2)`, Reducant `- I_(2)`
Discussion
19.

Identify the substance oxidised, reduced , oxidising agent and reducing agent for each of the following reactions : (a) 2AgBr(s)+C_6H_6O_2(aq) rarr2Ag(s)+2HBr(aq)+C_6H_4O_2(aq) (b) HCHO(l) +2[Ag(NH_3)_2]^(2+)(aq) +3OH^(-) (aq) rarr 2Ag(s) + HCOO^(-)(aq) +4NH_3(aq) +2H_2O(l) (c) HCHO(l)+2Cu^(2+)(aq)+5OH^(-)(aq) rarrCu_2O(s)+HCOO^(-) (aq)+3H_2O(l) (d) N_2H_4(l)+2H_2O_2(l)rarrN_2(g) +4H_2O(l) (e) Pb(s) + PbO_2(s) +2H_2SO_4(aq)rarr2PbSO_4(s)+2H_2O(l)

Answer»

Solution :
`PbO_2` : REDUCED `""Pb(s)` , oxidised
`PbO_2(s)` : oxidising AGENT , `Pb(s)` : reducing agent
Discussion
20.

Identify the structure of P :

Answer»


Answer :`CH_(3)-OVERSET(O)overset(||)(C)-CH_(2)-CH_(3)`
Discussion
21.

Identify the structure of X :

Answer»


ANSWER :`(##RES_CHM_SIPOC_E01_013_A01##)`
Discussion
22.

Identify the structure of amine.

Answer»


ANSWER :`CH_(3)-OVERSET(CH_(3))overset(|)(N)-CH_(3)` (`3^(@)` AMINE)
Discussion
23.

Identify the strongest and weakest reducing agents from the following list : Zn,Cu,Ag,Na,Sn.

Answer»

SOLUTION :Strong reducing agent is Zn and the WEAKEST reducing agent is Ag.
Discussion
24.

Identify the strongest acid among the following

Answer»

`CH_(3)CN`
`CH equiv CH`
`CH equiv CH`
`(CH_(3))_(3)CH`

ANSWER :C
Discussion
25.

Identify the state functions and path functions out of the following : enthalpy , entropy , heat, temperature, work , free energy.

Answer»

Solution :State function `:` ENTHALPY, Entropy , TEMPERATURE, Free energy, PATH functions`:` HEAT, work.
Discussion
26.

Identify the state quantity among the following

Answer»

1) q
2) q-w
3) q+w
4) w

Answer :B
Discussion
27.

Identify the state functions and path functions out of the following : enthalpy, entropy, heat, temperature, work, free energy.

Answer»

Solution :STATE functions are those VALUES which DEPEND only on the state of the system and not on how it is reached. e.g., enthalpy, ENTROPY, TEMPERATURE and free energy.
Path functions are those values which depend on the path of the system e.g., heat and work.
Discussion
28.

Identify the state functions and path functions out of the following enthalpy, entropy, heat, temperature, work, free energy

Answer»

SOLUTION :State functions are those values which DEPEND only on the state of the SYSTEM and not on how it is reached e.g., ENTHALPY, entropy, temperature and free energy. Path functions are those values which depends on the path of the system e.g., heat and work
Discussion
29.

Identify the state and path functions out of the following: (a) Enthalpy (b)Entropy (c) Heat (d) Temperature (e) Work (f) Free energy.

Answer»

SOLUTION :STATE function: Enthalpy, entropy, temperature and FREE energy.
PATH function: Heat and work.
Discussion
30.

Identify the species in which iron has lowest oxidation state?

Answer»

`FE(CO)_5`
`Fe_(2)(CO)_9`
`Fe_(0.94)O_1`
`K_4[Fe(CN)_6]`

Solution :In both `[Fe(CO)_5] and [Fe_2(CO)_9]`, the oxidation state of IRON is zero
Discussion
31.

Identify the set of "reagents" // "reaction" conditions 'X' and 'Y' in the following set of transformation : CH_(3)-CH_(2)-CH_(2)Br overset(X)to "Product" overset(Y)to CH_(3)-underset(Br)underset(|)CH-CH_(3)

Answer»

X = dilute AQUEOUS SOLUTION, `20^(@) C`,
`Y = "HBr" // "acetic ACID"` at `20^(@) C`
X = dilute aqueous NaOH, `20^(@) C`,
`Y = "HBr" // "acetic acid"` at `20^(@) C`
X = dilute aqueous NaOH, `20^(@) C`,
`Y=Br // CHCl_(3)`, `0^(@) C`
X = CONCENTRATED alcoholic NaOH, `80^(@) C`,
`Y=Br // CHCl_(3)`, `0^(@) C`

Answer :B
Discussion
32.

Identify the set of reagents/reactions conditions 'X' and 'Y' in the following set of transformations. CH_3-CH_2-CH_2Broverset(X)to"product"overset(Y)to CH_3-undersetunderset(Br)(|)CH-CH_3

Answer»

X=concentrated alcoholic NaOH, `80^@C`, Y=HBr acetic acid , `20^@C`
X=dil.aq. NaOH , `20^@C` , Y=HBr/acetic acid , `20^@C`
X=dil.aq. NaOH , `20^@C, Y=Br_2//CHCl_3` , `0^@C`
X=conc.alc.NaOH, `80^@C`, Y=`Br_2//CHCl_3,0^@C`

Answer :A
Discussion
33.

Identify the secondary pollutant among the following

Answer»

`CH_4`
Peroxy ACETYL NITRATE
`SO_2`
`NO`

ANSWER :B
Discussion
34.

Identify the redox reaction out of the following reactions and identify the oxidising and reducing agents in them. (a) 3HCl_((aq))+HNO_(3(aq))toCl_(2(g))+NOCl_((g))+2H_(2)O_((l)) (b) HgCl_(2(aq))+2KI_((aq))toHgI_(2(s))+2KCl_((aq)) ( c) Fe_(2)O_(3(s))+3CO_((g))overset(Delta)to2Fe_((s))+3CO_(2(g)) (d) PCl_((l))+3H_(2)O_((l))to3HCl_((aq))+H_(2)PO_(3(aq)) (e) 4NH_(3(aq))+3O_(2(g))to2N_(2(g))+6H_(2)O_((g))

Answer»

Solution :(a) `overset(-1)(3HCl_((AQ)))+overset(+5)(HNO_(3(aq)))tooverset(0)(Cl_(2(g)))+overset(+3)(NOCl_((g)))+2H_(2)O_((l))`
Oxidation number of elements are change so this is redox reaction. HCl is reducing agent and `HNO_(3)` is oxidising agnet.
(b) `Hgoverset(-1)(Cl_(2(aq)))+overset(-1)(2KI_((aq)))toHgoverset(-1)(I_(2(s)))+2Koverset(-1)(Cl_((aq)))`
This is not redox reaction.
( c) `overset(+3)(Fe_(2))O_(3(s))+overset(+2)(3CO_((g)))tooverset(0)(2Fe_((s)))+overset(+4)(3CO_(2(g)))`
Oxidation number of OXYGEN is changed so this is redox reaction. CO is reducing agent and `Fe_(2)O_(3)` is oxidising agnet.
(d) `overset(+3)(P)overset(-1)(Cl_(3(l)))+3H_(2)O_((l))to3Hoverset(-1)(Cl_((aq)))+H_(2)overset(+3)(PO_(3(aq)))`
This reaction is not redox reaction.
(e) `overset(+3)(4NH_(3(aq)))+overset(0)(3O_(2(g)))tooverset(0)(2N_(2(g)))+6H_(2)overset(-2)(O_((g)))`
This is redox reaction. `O_(2)` is oxidising agnet `NH_(3)` is reducing agent.
Discussion
35.

Identify the redox reaction out of the following reaction and identify the oxidising and reducing agents in them (i)3HCI (aq) +HNO_(3)(aq) rarr CI_(2)(g)+NOcI(g)+2H_(2)O(l) (ii) HgCI(aq)+2 KI(aq)rarrHgI_(2)(s)+2 KCI(aq) (iii) Fe_(2)O_(3)(s)+3CO(g)rarr2Fe(s)+3CO_(2)(g) (iv) PcI_(3)(l)+3H_(2)O(l)rarr3 HCI(aq)+H_(3)PO_(3)(aq) (v) 4NH_(3)+3O_(2)(g)rarr2N_(2)(g)+6H_(2)O(g)

Answer»

Solution :(i) writing the O.Non each atom above its symbol we hve
here the O.N of CI increase from -1 in HCI to 0 in `CI_(2)` THEREFORE `CI^(-)` is oxidised and HENCE HCI acts as the reducing agent
The O.N of Ndecreases from +5 in `HNO_(3)` to +3 in NOCI therefore `HNO_(3)` acts as the oxidising agent thus reaction (i) is a redox rection ltbRgt (ii) writing the O.N of each atom abvoe its symbol we have
therefore the O.N of none of the atoms undergo a change therefore raction (ii) is not a redox reaction
(iii) here O.N of fe decreases from +3 in `Fe_(2)O_(3)` to O in Fe therefore `Fe_(2)O_(3)` acts as an oxidising agent further O.N of C increases from +2 in CO to +4 `CO_(2)` therefore reaction (iv) is not a redox reaction (v) writing the O.N of each atom above its symbol we have
Here O.N of N increase from-3 to o in `N_(2)`therefore `NH_(3)` acts as a an reducing agent further O.N of O decrease from 0 in `O_(2)` to -2 in `H_(2)O` therefore `O_(2)` acts as a oxidsing agent thus reaction (v) isredox reaction
Discussion
36.

Identify the reagents shown in bold in the following equations as nucleophiles or electrophiles (a) CH_(3)COOH + HO^(-) rarr CH_(3)COO^(-) + H_(2)O (b) CH_(3)COCH_(3) + .^(-)CN rarr (CH_(3))_(2)C(CN)(OH) (c) C_(6)H_(6) + CH_(3)overset(+)(C)O rarr C_(6)H_(5)COCH_(3)

Answer»

SOLUTION :NUCLEOPHILES : (a) and (B) ELECTROPHILE : (C).
Discussion
37.

Identify the reagents shown in bracketts as nucleophile or electrophile CH_3COOH+[OH^-] rarr CH_3COO^-+H_2O

Answer»


ANSWER :`OH^-` (NUCLEOPHILE)
Discussion
38.

Identify the reagents shown in bracketts as nucleophile or electrophile CH_3COCH_3+[CN^-] rarr (CH_3)_2C (CN)(OH)

Answer»


ANSWER :`CN^-` (NUCLEOPHILE)
Discussion
39.

Identify the reagents shown in bracketts as nucleophile or electrophile C_6H_6+[CH_3-CO] rarr C_6H_5-CO-CH_3

Answer»


ANSWER :`CH_3OH` (ELECTROPHILE)
Discussion
40.

Identify the reagents shown in boid in the following equations as nucleophiles or electrophiles: (a) CH_(3)COOH + HO^(-) rarr CH_(3)COO^(-) + H_(2)O (b) CH_(3)COCH_(3) + bar(C )N rarr (CH_(3))_(2)C(CN)(OH) (c ) C_(6)H_(5) + CH_(3) overset(+)(C )O rarr C_(6)H_(5)COCH_(3)

Answer»

SOLUTION :More suitable (c ) `C_(6)H_(5) + CH_(3) overset(+)(C )O rarr C_(6)H_(5)COCH_(3) + H^(+)` and (b) `CH_(3)COCH_(3) + H^(+) CN^(-) rarr (CH_(3))_(2) C(CN) (OH)`
`because` Need to charge balance
`{:("(a)" HO^(-)"is nucleophile reagent"),("(b)" ""^(-)CN "is NUCLEOPHILIC reagent"):}} {:("Because of (-)charge and octet so it is electron rich""):}`
(c ) `CH_(3) overset(+)(C )O` is electrophilic because on CARBON sixtet, vacant orbital and electron deficient
Discussion
41.

Identify the reagent which can easily distinguish between 1-butyne and 2-butyne.

Answer»

BROMINE water
Baeyer's reagent
Dilute `H_(2)SO_(4)+HgSO_(4)`
AMMONIACAL `Cu_(2)Cl_(2)`

Answer :D
Discussion
42.

Identify the reagent from the following list which can easily distinguish between 1-butyne and 2-butyne

Answer»

bromine , `C Cl_4`
`H_2`, Lindlar CATALYST
dilute `H_2SO_4, HgSO_4`
ammoniacal `Cu_2Cl_2` SOLUTION

Solution :Amm. `Cu_2Cl_2` reacts with 1-butyne but not with 2-butyne
Discussion
43.

Identify the reaction in which the heat liberated corresponds to the heat of formation (Delta H_(f)):

Answer»

`C _(("diamond")) + O _(2 (G)) to CO _(2(g)) +` heat
`2 H _(2 (g)) + O _(2 (g)) to 2 H _(2) O _((g)) + `heat
`C _(("diamond")) + 2H _(2 (g)) to CH _(4(g)) + ` heat
`S _(("RHOMBIC")) + O _(2 (g)) to SO _(2 (g)) +` heat

Answer :D
Discussion
44.

Identify the products in the following reactions giving their stereoisomers ( if any ) . a. (B) overset(H_(2)+Pt)rarrC ( No. of isomers ) b. (B)(from Problem A) overset(Baeyer's)underset(reag e nt)rarr (D)+(E)( Colour of precipitate) c. (B) overset(PhCO_(3)H)underset (+H_(2)o)rarr(D) d.(A)underset(Na+liq. ND_(3)+EtOH)rarr(F) overset(Alk. KMnO_(4))underset(OSO_(4)//NaHSO_(3) or PhCO_(3)H//H_(2)O)rarr(D)

Answer»

Solution :`a.`
`(B)` is a cis compouind and the addition of `H_(2)+Pt` isalso syn. But `(B)` has two different `(R)` groups`(Me` and `Et)` , so the product `(C)` will not be meso but a racemic compound.
Since `(C)`contains two chiral CENTRES, the number of OPTICAL isomers will be `2^(2)=4(` two pairs of entantiomers `).` These are `:`

`I` and `II,III` and `IVimplies ` Pairs of enentiomers
`(I, III), (I,IV),(II,IV)` and `(II,IV)implies ` Pairs of diastereomers.
`b.`

c.`UNDERSET("R groups")underset("with two different")underset("cis-Compound")((B))overset(PhCO_(3)H+H_(2)O)underset("Anti-hydroxylation")rarr(D)` [As in (b)]
d.
Discussion
45.

Identify the products among the following .

Answer»




Solution :ACETAL FORMATION to PROTECT KETONE, followed by OZONOLYSIS and repete acetal.
Discussion
46.

Identify the product S in the following series of operations : C_(2)H_(2) underset(Hg^(2+))overset(dil. H_(2)SO_(4))rarr (P) overset(K_(2) Cr_(2) O_(7) // H^(+))rarr (Q) overset(CaCO_(3))rarr (R) overset(Delta) rarr (S)

Answer»

Ethyl alcohol
acetaldehyde
acetone
acetic acid

Solution :`CH -= underset(Hg^(2+))overset(Dil. H_(2)SO_(4))rarr underset((P))(CH_(3)CHO) overset(K_(2)Cr_(2)O_(7) //H^(+))rarr underset((Q))(CH_(3)COOH) overset(CaCO_(3))rarr underset((R))((CH_(3)COO)_(2)CA) overset(DELTA)rarr underset((S))(CH_(3)COCH_(3))`
Discussion
47.

Identify the product of the following elimination reaction X and Y respectively with stereochemistry :

Answer»




ANSWER :C
Discussion
48.

Identify the product of the following condensation reaction

Answer»




SOLUTION :
Discussion
49.

Identify the product in the reaction PhC -=Cme overset(H_3O^(+), Hg^(2+)) to?

Answer»

`PhCH_2CH_2CHO`
`PhCOCH_2CH_3`
`PhCH_2COCH_3`
PhCOCOMe

Answer :B
Discussion
50.

Identify the product in the following reaction. PhC-=C Me overset(H_3O^+, Hg^(2+))to

Answer»

Solution :First of all `Hg^(2+)` ions form a complex (I) with the alkyne. The complex formed here is , however UNSYMMETRICAL in which the +ve charge LIES on the carbon ATTACHED to the Ph ring since it is stabilized by resonance with the double bonds of the Ph ring. Later on nucleophilic attack of `H_2O` on this carbon ultimately leads to enol (II) which tautomerises to give ketone (III) .
Discussion